Sudden death in a 27-year-old man with Chiari I malformation.

We present a case of a witnessed sudden death of a 27-year-old adult man with no antecedent trauma who subsequently was found to have a previously undiagnosed Chiari I malformation. Cases of sudden unprovoked respiratory collapse in children and adults with Chiari I malformation have been well documented, leading to death in some children. There have also been rare examples of sudden death in adults with Chiari I malformation; however, these decedents experienced recent trauma. This is a unique example of a witnessed sudden death of an adult with previously undiagnosed Chiari I malformation in the absence of trauma.